Fuel injection systems typically employ multiple fuel injectors to inject fuel into combustion chambers of an engine. This fuel is supplied to the fuel injectors via a common manifold secured to the engine and individual supply lines connected between the common manifold and the injectors.
The presence of air mixed into the fuel can undermine the performance of the fuel injection system, such as a pump and line system. For example, pressurizing the mixture of air and fuel may cause damage to the pump. Furthermore, mixing of the air into the fuel supply can be undesirable in higher pressure systems because it can cause actual combustion characteristics to deviate from expected combustion characteristics, potentially undermining the control of the combustion process. Deaeration of the fuel is desirable so that the pump performs in a predictable manner.
One method of separating air from fuel is described in U.S. Pat. No. 5,884,809 (“the '809 patent”) to Wood et al. The '809 patent describes a system for dispensing fuel into a fuel tank in a vehicle. The system includes an air separator having an air separation chamber with a conical lower section. A fuel stream is introduced into an upper section of the air separation chamber such that the fuel stream flows in a cyclonic flow pattern. Air is forced toward the center of the air separation chamber and downwardly into a bleed tube. The fuel, from which the air has been removed, is discharged from an opening at the base of the conical lower section and then flows to a dispenser head for dispensing the fuel into the vehicle.
Although the system of the '809 patent may provide a fuel dispensing system that is capable of separating air from fuel, providing a central opening at the base of the air separation chamber for the fuel may allow more air to remain in the fuel that exits from the air separation chamber, thereby providing poor efficiency and inadequate air removal. Furthermore, the bleed tube of the '809 patent allows both the air and the fuel to exit downwardly from the air separation chamber via adjacent openings. However, this may allow the air and fuel to mix again, thereby also reducing efficiency of the air separator and providing unacceptably high air content in the fuel. In addition, the air separator of the '809 patent is directed towards removing air prior to being dispensed into a fuel tank of a vehicle and does not address the problems of removing air in a fuel injection system.
The disclosed system is directed to overcoming one or more of the problems set forth above.